分子光谱法用于环境中手性农药的分析研究

发布时间：2018-05-31 14:42

本文选题：共振瑞利散射 + 荧光光谱法　；参考：《重庆三峡学院》2017年硕士论文

【摘要】：农药是用于防治危害农作物及农副产品的病虫害、野杂草及其它有害生物的化学药品的统称,它们可来源于人工合成的化合物,也可来源于自然界的天然产物。农药作为一种两面性物质,其对农业生产或卫生除害方面有益,但同时也会造成环境污染问题,迫害生态环境健康或人体健康。世界各国都出台了相关的标准,规定了各种农药在各环境中的最大残留量,或是规定了每日允许摄入量。这充分说明了人们对农药污染问题非常的重视,对农药对人体健康的影响十分的关注。因此,分析测定各环境中农药残留对于保护生态环境健康或人体健康来说是至关重要和必要的。本研究主要是借助分子光谱手段(共振瑞利散射技术和荧光光谱法)分析与测定环境中的农药残留。目前市场上所售卖的手性农药约占农药种类的40%。而本实验主要的研究对象就是手性农药马拉硫磷、精喹禾灵,以及农药草甘膦。研究了分析对象与光探针试剂(色氨酸、曙红Y、氯化钯以及硝酸铜)之间相互作用对体系共振瑞利散射或体系荧光的影响。本文考察了光谱特征、最佳的反应条件及其相关的影响因素,分别建立了共振瑞利散射技术对手性农药马拉硫磷或精喹禾灵进行测定,建立了荧光光谱法对农药精喹禾灵或草甘膦进行测定,并且对体系的反应机理、散射增强以及荧光猝灭等原因分别进行了研究和讨论。并且将建立的方法运用到实际样品的测定中,结果较为满意。本文在国家自然科学基金(No.21175015;No.21475014)的资助下完成,其主要研究内容如下:1.色氨酸-Pd(Ⅱ)-马拉硫磷三元体系的荧光和共振瑞利散射光谱研究及其分析应用基于色氨酸-氯化钯-马拉硫磷体系的共振瑞利散射(RRS)增强建立了一种方便、简单快速的方法用以测定农药马拉硫磷。利用荧光光谱、共振瑞利散射技术以及紫外-可见吸收光谱研究了色氨酸、氯化钯(Pd(Ⅱ))和马拉硫磷三者之间的反应。在最佳的反应条件下,色氨酸-钯-马拉硫磷体系的共振瑞利散射显著增强,这是由于马拉硫磷的酸解产物与钯和色氨酸通过静电作用和疏水作用结合生成了新的三元螯合物,从而导致体系的共振瑞利散射增强,且增强的强度与马拉硫磷的浓度在一定的范围内呈线性关系。同时还考察了共存物质对体系共振瑞利散射的影响,结果表明体系具有良好的抗干扰能力。新创建的共振瑞利散射方法可以用于实际样品中马拉硫磷的测定,且结果较为满意。2.氯化钯-精喹禾灵二元体系的共振瑞利散射、二级散射和倍频散射光谱研究及其分析应用利用共振瑞利散射技术、二级散射技术、倍频散射技术以及紫外-可见吸收光谱研究了氯化钯(Pd(Ⅱ))和精喹禾灵(Qpe)间的相互反应。基于光谱图的变化,我们可以推断在最佳反应条件下,氯化钯和精喹禾灵间反应生成了 Pd(Ⅱ)-Qpe离子缔合物,从而导致体系的共振瑞利散射、二级散射、倍频散射显著增强。散射增强的强度与精喹禾灵的浓度在一定范围内呈正比例关系。实验还考察了共存物质对体系共振瑞利散射的影响,结果表明体系具有良好的抗干扰能力。因此,建立了测定精喹禾灵的共振瑞利散射方法、二级散射法和倍频散射法。共振瑞利散射法测定精喹禾灵的检出范围为0.2-1.4μg/mL,最低检出限为55.4 ng/mL。实验讨论了氯化钯和精喹禾灵间可能的反应机理和共振瑞利散射增强的原因。共振瑞利散射法较其它方法有较好的选择性,可以成功的用于实际样品中精喹禾灵的测定,且结果令人满意。3.曙红Y作光探针的荧光猝灭法测定精喹禾灵的研究及其分析应用一种方便、简单快速的测定精喹禾灵的荧光猝灭法得以建立。曙红Y(EY)是一种红色染料,具有较强的绿色荧光(λex/λem = 519/540 nm)。利用荧光光谱、共振瑞利散射技术以及紫外-可见吸收光谱研究了曙红Y、氯化钯(Pd(Ⅱ))和精喹禾灵三者之间的相互反应。根据光谱图的变化,可以推断Pd(Ⅱ)与Qpe反应提供了带正电荷的螯合物,然后通过静电作用和氢键作用与带负电荷的EY反应生成三元螯合物。在最佳条件下,有Pd(Ⅱ)存在的曙红Y体系荧光可以被精喹禾灵猝灭且体系RRS信号显著增强,荧光强度和RRS强度变化与精喹禾灵的浓度呈一定线性关系。基于体系的荧光猝灭,建立了一种新颖、方便的荧光法用于测定精喹禾灵。该法测定精喹禾灵的检出范围为0.04-1.0 μg/mL,最低检出限为20.3 ng/mL。把该法与其它方法比较,具有较高的灵敏度和较大的检出范围。同时实验也考察了共存物质对体系的影响,结果表明体系具有良好的抗干扰能力。新创建的共振瑞利散射方法可以用于实际样品中精喹禾灵的测定,且结果较为满意。4.色氨酸作光探针的荧光"关-开"法测定草甘膦的研究及其分析应用色氨酸(Try)作为一种芳香烃氨基酸,具有较强的荧光(λex/λem = 279/355 nm)。色氨酸荧光在pH为6.24的磷酸盐(Na2HP04-KH2PO4)缓冲溶液中可被钯离子(Pd(Ⅱ))显著猝灭,在pH为8.67的磷酸盐缓冲液中可被铜离子(Cu(Ⅱ))显著猝灭,同时向两体系中加入农药草甘膦(Gly),体系的荧光都得到恢复。对比在最佳条件下Try-Pd(Ⅱ)体系和Try-Cu(Ⅱ)体系测定草甘膦,Try-Cu(Ⅱ)体系具有较好的灵敏度、准确性以及抗干扰能力。实验分别讨论了 Try-Pd(Ⅱ)体系和Try-Cu(Ⅱ)体系中各物质间的反应,考察了各体系最佳的反应条件,同时也详细的研究了共存物质对体系的影响。Try-Cu(Ⅱ)体系测定草甘膦的检出范围为0.025-1.0 μg/mL,最低检出限为8.6 ng/mL。把创建的方法用于实际样品中草甘膦的测定,结果表明,Try-Cu(Ⅱ)体系对草甘膦的测定结果更有效、更准确。因此,基于色氨酸荧光的"关-开"效应,建立了简单、快速测定草甘膦的荧光光谱法。
[Abstract]:Pesticides are used to prevent and control diseases and pests of crops and agricultural and sideline products, the chemical drugs of wild weeds and other harmful organisms. They can be derived from synthetic compounds and natural natural products. As a two sided substance, pesticides are beneficial to agricultural production or sanitation, but they will also be used. Environmental pollution problems, persecuting the health of the ecological environment or human health, all countries in the world have issued relevant standards, which stipulate the maximum amount of pesticide residues in the environment, or the daily allowable intake. This fully illustrates that people pay great attention to the problem of pesticide pollution and the effect of pesticide on human health. Therefore, the analysis and determination of pesticide residues in various environments is essential and necessary for the protection of ecological environment health or human health. This study is mainly based on molecular spectroscopy (resonance Rayleigh scattering and fluorescence spectrometry) for the analysis and determination of pesticide residues in the environment. The main object of this study is 40%., the chiral pesticide malathion, praziprine, and pesticide glyphosate. The effects of the interaction between the analysis object and the light probe reagents (tryptophan, eosin Y, palladium chloride and copper nitrate) on the system resonance Rayleigh scattering or system fluorescence are studied. Characteristics, the optimum reaction conditions and the related factors, the resonance Rayleigh scattering technique was established to determine the adversary pesticide malathion or quetialine respectively. The fluorescence spectrometry was established for the determination of quetialine or glyphosate, and the reaction mechanism, the scattering enhancement and the fluorescence quenching were respectively introduced. The research and discussion are carried out and the method is applied to the determination of actual samples. The results are satisfactory. The main contents of this paper are as follows: the fluorescence and Resonance Rayleigh scattering spectra of 1. tryptophan -Pd (II) -Pd (II) - malathion system and the study of the resonance Rayleigh Scattering Spectra. Based on the resonance Rayleigh scattering (RRS) enhancement of tryptophan palladium chloride malathion system, a convenient, simple and fast method was established for the determination of malathion in the pesticide. The fluorescence spectra, resonance Rayleigh scattering and UV visible absorption spectra were used to study the three cases of tryptophan, palladium chloride (Pd (II)) and malathion. In the optimum reaction conditions, the resonance Rayleigh scattering of the tryptophan palladium malathion system is enhanced significantly, due to the formation of a new three element chelate by the combination of palladium and tryptophan by the combination of palladium and tryptophan by electrostatic interaction and hydrophobicity, resulting in enhanced resonance Rayleigh scattering of the system and the intensities and intensities of the system. The concentration of malathion is linear in a certain range. The effect of the coexistent substance on the resonance Rayleigh scattering of the system is also investigated. The results show that the system has good anti-interference ability. The newly created Resonance Rayleigh scattering method can be used for the determination of malathion in the actual samples, and the results are more satisfactory for.2. palladium chloride arginine. The resonance Rayleigh scattering of the two element system, the study of the two stage scattering and frequency doubling scattering spectrum and its application, the interaction between palladium chloride (Pd (II)) and quetialine (Qpe) is studied by Resonance Rayleigh scattering, two order scattering, frequency doubling scattering and UV visible absorption spectroscopy. It is inferred that the inter reaction of palladium chloride and ququinaline produced the Pd (II) -Qpe ionic association under the optimal reaction conditions, which resulted in the resonance Rayleigh scattering of the system, the two stage scattering, and the significant enhancement of the frequency doubling scattering. The intensity of the scattering enhancement was proportional to the concentration of quaziprine in a certain range. The experiment also examined the coexisting substance pair. The effect of Resonance Rayleigh scattering shows that the system has good anti-interference ability. Therefore, the resonance Rayleigh scattering method for the determination of quetialine, two stage scattering and frequency doubling scattering, the detection range of quetialine by Resonance Rayleigh scattering method is 0.2-1.4 mu g/mL, and the minimum detection limit is 55.4 ng/mL., and the chlorination is discussed. The possible mechanism of the reaction between palladium and quetialine and the reason for the enhancement of Resonance Rayleigh scattering. The resonance Rayleigh scattering method has better selectivity than the other methods. It can be successfully used for the determination of ququprazine in actual samples, and the results are satisfactory and the fluorescence quenching method of.3. eosin Y as a light probe for the determination of quetialine and its analysis should be satisfactory. A convenient, simple and fast fluorescence quenching method for the determination of quaziprine was established. Eosin Y (EY) was a red dye with a strong green fluorescence (lambda ex/ EM = 519/540 nm). The three cases of eosin Y, palladium chloride (Pd (II)) and quetialine were studied by fluorescence spectroscopy, resonance Rayleigh scattering and UV visible absorption spectra. The interaction between the Pd (II) and the Qpe reaction provides a positive charge chelate, and then the three element chelate is generated by the electrostatic interaction and hydrogen bonding with the negatively charged EY reaction. Under the optimum conditions, the eosine Y system fluorescence in Pd (II) can be quenched by the fine quinolin and the system RRS signal The fluorescence intensity and the intensity of RRS were linearly related to the concentration of ququinoline. Based on the fluorescence quenching of the system, a novel and convenient fluorescence method was established for the determination of ququprazine. The detection range of ququprazine was 0.04-1.0 g/mL, and the minimum detection limit was 20.3 ng/mL.. The method was compared with other methods. The results show that the system has good anti-interference ability. The newly created Resonance Rayleigh scattering method can be used for the determination of kququazine in actual samples, and the results are more satisfied with the fluorescence of.4. tryptophan as a light probe. The study and analysis of glyphosate by method and its analysis and application of tryptophan (Try) as an aromatic amino acid with strong fluorescence (lambda ex/ lambda EM = 279/355 nm). The fluorescence of tryptophan in a phosphate (Na2HP04-KH2PO4) buffer solution of pH 6.24 can be significantly quenched by palladium ions (Pd (II)) and can be copper ions in the phosphate buffer solution of pH 8.67. Cu (II)) was significantly quenched. At the same time, the fluorescence of the system was restored by adding pesticide glyphosate (Gly) into the two system. Compared with the optimum conditions, the Try-Pd (II) system and the Try-Cu (II) system were used to determine glyphosate, and the Try-Cu (II) system had good sensitivity, accuracy and anti-interference ability. The experiment discussed the Try-Pd (II) system and Try-Cu (Try-Cu (II) respectively. II) the reaction between the various substances in the system, the optimum reaction conditions of each system were investigated, and the effects of the coexisting substances on the system were also studied in detail. The detection range of glyphosate was 0.025-1.0 g/mL, and the minimum detection limit was 8.6 ng/mL.. The established method was used for the determination of glyphosate in actual samples. The results showed that the method was used for the determination of glyphosate in the actual samples. The Try-Cu (II) system is more effective and more accurate for the determination of glyphosate. Therefore, based on the "turn off" effect of tryptophan fluorescence, a simple and fast fluorescence spectrometric method for the rapid determination of glyphosate is established.
【学位授予单位】：重庆三峡学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;X839.2

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